1. Field of the Invention
This invention relates to battery terminal clamps and, more particularly, to battery terminal clamps for securing an electrical conductor to a battery terminal which utilizes a dielectric block generally covering the conductive portions of the clamp apparatus.
2. Description of the Prior Art
Battery terminals are generally a continuing source of potential problems in automotive and related applications. Acidic fumes given off by the battery result in corrosion building up on the battery, and particularly on the battery terminals. The positive terminal of batteries is generally the location at which the most corrosion builds up. Corrosion, to a lesser extent, builds on the negative battery terminal, also.
When corrosion builds up on a battery terminal to the extent that it interfers with the electrical contact between the battery terminal and the clamp or connector which electrically connects an electrical cable to a battery, a deterioration in the electrical system of the vehicle occurs. Ultimately, the deterioration results in a failure of the vehicle's electrical system. This is generally caused by an increase in resistance between the battery terminal and the attached cable and, ultimately, a cessation or breaking of electrical contact due to the corrosion.
There have been several prior art attempts to minimize the corrosion problem. One such attempt resulted in the movement of the battery terminals from the top of a battery to the side of a battery. This has had some positive effects, but it also has had some problems. It has, to some extent, solved part of the corrosion problem, since the battery fumes generally migrate across the top of the battery and outwardly, rather than downwardly. A major problem has been in the connecting of jumper cables to the side terminals.
Another attempt to solve the problem has been to use chemically impregnated washers on the battery terminals beneath the cable connectors. The chemicals in the washers, which are generally made of felt, chemically inhibit the formation of the corrosion by neutralizing the acidic gases as the gases emanate from the battery. However, over an extended period of time the chemical inhibitor is exhausted, and corrosion then builds up.
One of the simplest attempts to solve the corrosion problem is to coat the cable clamp and exposed portion of the battery terminal post with a relatively thick coating of grease. The grease acts as a protective coating which seals out the corrosive gas fumes from the battery. As in the other attempts to solve the problem, ultimately the grease wears away or is rubbed off, etc., and the terminal and clamp are then susceptible to the build-up of the corrosion. The grease poses other problems, too. The grease holds dust, dirt, and other particulates. The grease also easily rubs off on clothing, skin, etc., if a person inadvertently comes too close when the hood is open.
As discussed above, there are basically three approaches to the problem of battery corrosion, relocation of the terminals, use of a chemical corrosion inhibitor, as in the chemically impregnated felt washers, and a protective coating over the battery terminal and cable connector. None of the approaches is completely satisfactory for the reasons set forth. For a long time period solution, the chemical inhibitor and protective coatings have the same fundamental problem in that they ultimately wear out or lose their effect, leaving the battery cable and terminal open to the attack of the corrosive gases from the battery.
The battery side terminal situation is awkward, particularly in adapting the battery cables to the side terminal batteries, and also in utilizing the positive terminal of the battery for purposes of jumping batteries, when such is required. Moreover, a majority of batteries in vehicles currently use the top terminals rather than side terminals. The corrosion problem accordingly is a continuing problem.
Battery manufacturers themselves have taken another step in helping to solve the problem and in trying to develop a battery which lasts a maximum length of time. This has been accomplished by the design of different types of batteries, using different electrolytes, and by then "sealing" the battery. Rather than use the sulfuric acid which is and has been the most widely used electrolyte, new electrolytes have been developed, which allow a battery to be relatively maintenance free, since the addition of water is a minimum problem. Since a battery is "sealed", comparatively few of the acidic gases are vented from the battery. However, in batteries which require the addition of water on a periodic basis, the venting of the battery cells is the primary source of the corrosive gases. The latter batteries, which require the periodic addition of water, are still the most prevalent batteries available on the market today.
Another possible solution to the problem is illustrated in U.S. Pat. No. 4,372,636, dated February 8, 1983, the inventor of which is the inventor of the present apparatus. In the '636 apparatus, plastic caps are used to secure cables to battery terminals.